Merrick has previously been fined by Football Federation Australia (FFA) for code of conduct breaches for comments about referees.

He was fined $3,000 in February this year for comments about the video assistant referee (VAR) - the penalty was rescinded on appeal.

In March last year, Merrick was fined $3000 for labelling refereeing and the use of VAR as "disgraceful" after an A-League game.

An FFA spokesman had no comment on Wednesday in regards to Merrick's latest comments.

Merrick was also upset with two other controversial calls which went against the Jets as they were tipped out of the Cup.

Goalkeeper Lewis Italiano was given a straight red in the 10th minute for a challenge outside his area which referee Daniel Elder believed was a 'last man' foul, but Merrick felt it was an incorrect call.

And the veteran coach said a "blatant hand ball" by Adelaide captain Michael Jakobsen should have resulted in a Jets penalty but didn't.

"We have still got this system where the referees don't seem to refer to the linesmen and the linesmen don't say anything," he said.

Meanwhile, the Jets have announced the signing of Northern Ireland under-21 international Bobby Burns on a season-long loan deal.

Burns, a 19-year-old left-back, has been loaned by Scottish Premier League club Heart of Midlothian.